1. Field of the Invention
The present invention relates to a photographic film curling correcting method and apparatus for correcting curling of photographic film generated when the photographic film is stored in a cartridge in which the photographic film is taken up around a shaft in the form of a roll and is accommodated.
2. Description of the Related Art
After being photographed, a photographic film is loaded and accommodated in a cartridge. In a so-called strip processing developing apparatus in which the photographic film is withdrawn from the cartridge and is subject to developing processing, it is detected that the photographic film is completely withdrawn from the cartridge, the final end of the photographic film is cut, and processing is effected continuously. A guiding member, called a short leader, is adhered to the leading end portion of the photographic film. As the short leader is guided and conveyed, developing processing and photosensitive processing are effected. In this type of strip processing, curling of the leading end portion of the photographic film is eliminated by the short leader. However, when the photographic film is taken up onto the spool, curling is most strong at the lowermost layer (i.e., the trailing end portion). Therefore, when the photographic film is curled in the form of a loop, the loop is crushed by a roller, and the photographic film is bent.
In recent years, a system has been proposed in which the photographed photographic film is taken up again into the cartridge and returned to the customer in that way. In such a case, it is possible to have the tongue remain out of the cartridge by reversely rotating the spool shaft on which the photographic film is accommodated. Therefore, when reprinting or the like is requested, the cartridge is loaded into the printing apparatus, and printing processing is effected.
The curling of the trailing end portion of the photographic film taken up in this type of cartridge is strong.
Further, as cameras are being made more compactly, the idea of accommodating photographic films in small cartridges has also been conceived. As in the above-described case, curling is strong in these small cartridges as well.
As a result, measures to correct curling in advance, such as attaching a short leader to the trailing end portion of the photographic film as well, have been proposed. However, when reprinting or the like is requested after initial printing (simultaneous printing) has been completed, i.e., for the second printing or times thereafter, the photographic film is directly loaded into a printing apparatus without being processed into strips. Therefore, the film must be dealt with in a state in which the curling thereof is strong.
It is best to continuously provide a conveying path, which can smoothly guide the curled photographic film, from the photographic film withdrawing position to the heating processing position. However, for example, when the loading portion into which the photographic film is loaded is a cassette-type loading portion which can be separated from the conveying path of the photographic film, it is necessary to transfer the photographic film between the loading portion and the conveying path of the photographic film.
However, because there is strong curling in the photographic film, the leading edge of the photographic film enters into the gap of the transferring portion at which the photographic film is transferred from the loading portion to the photographic film conveying path. Trouble in the conveying of the photographic film, such as jamming or the like, may therefore occur.
When a plurality of curled photographic films are processed, the photographic films are withdrawn one by one, and workability is poor. Therefore, a cassette-type loading portion in which a plurality of cartridges can be loaded is used. The plurality of loaded cartridges are successively positioned at a photographic film withdrawing position. The respective spool shafts of the cartridges loaded in the loading portion are respectively connected to gears provided in the loading portion. These gears mesh with a driving gear at the photographic film withdrawing position. In this way, a plurality of photographic films can be automatically processed.
The photographic film, which has undergone curling correcting processing, is taken up again into the cartridge. Therefore, when the loading portion is viewed from the exterior thereof, it cannot be determined if the cartridges loaded therein have been processed or have not yet been processed. Further, when the loading portion is not completely filled with cartridges, an empty section of the loading portion is positioned at the photographic film withdrawing position, and the apparatus may make an error in operation. Further, the processing time is made longer than necessary.
Moreover, when the cartridges are positioned successively, a shock is generated when the gears connected to the respective cartridges mesh with the driving gear at the predetermined position. There is therefore the fear that a loss of synchronism may be generated in the motor due to the step-movement of the loading portion.
Generally, a drum is optimal for curving the photographic film in a direction opposite to the curling thereof. A pair of flanges are formed on the drum in order to stably convey the photographic film. The photographic film is guided and conveyed by the pair of flanges.
Further, it is preferable that the outer circumference of the drum contacts a drive roller and that the drum is rotated by the driving of the drive roller because of the reduction in the torque of the shaft of the drum and because a heating means is accommodated within the drum.
However, when dirt adheres to the outer circumference of the drum and especially to the surface around which the photographic film is trained, the photographic film may be damaged or it may not be possible to effect stable heating processing or the like. Therefore, the outer circumference of the drive roller has adhesion, and the dirt adhering to the circumferential surface of the drum is removed in accordance with the rotation of the drive roller (i.e., the dirt adheres to the drive roller). When a predetermined amount of dirt has adhered to the heat roller, the heat roller may be changed.
However, because the flanges are formed on the drum, a portion of the drive roller is accommodated between the flanges. Therefore, it is necessary to remove the drum as well when the drive roller is changed when the predetermined amount of dirt is to be removed therefrom. Workability therefore deteriorates.